The present invention relates to a thin film transistor liquid crystal display (TFT-LCD) and a method of manufacturing the same.
Recently, as digital televisions are widely used, conventional CRT displays are gradually displaced by a new generation of displays because CRT displays have disadvantages of large volume, large weight, radiation and difficulty in digital application, etc. The representative new generation of displays includes plasma display panel (PDP), organic light-emitting display (OLED), liquid crystal display (LCD), etc. Among them, thin film transistor liquid crystal displays (TFT-LCDs) have advantages, such as, small volume, small weight, low power consumption, non-radiation, high display resolution, etc., and have gradually become the mainstream products in the display market.
The main configuration of a TFT-LCD includes an array substrate and a color filter substrate facing each other with a liquid crystal layer interposed therebetween. A plurality of gate lines, a plurality of data lines are formed on the array substrate and thin film transistors (TFTs) and pixel electrodes are arranged in an array defined by the gate lines and data lines on the array substrate. A counter electrode, color filters and the like are formed on the color filter substrate. Signals over the data lines are transmitted to the corresponding pixel electrodes under the control of the signals applied over the gate lines, and thereby the TFT-LCD can display desired images by generating electric fields between the pixel electrodes on the array substrate and the counter electrode on the color filter substrate so as to control the alignment of liquid crystal.
Since the manufacturing process of a TFT-LCD is very complicated, the display quality of a manufactured TFT-LCD may be seriously influenced when the manufacturing parameters deviate from the design requirements. For example, in manufacturing the array substrate of a TFT-LCD, light blocking bars are simultaneously formed when the gate lines of the array substrate are formed, and each of the light blocking bars is disposed at the periphery of a pixel electrode to prevent light from leaking therefrom; furthermore, a common voltage may be applied to the light blocking bars so that the light blocking bars can serve as common electrodes. In such a conventional pixel structure, parasitic capacitance is formed between a pixel electrode and a corresponding data line with a passivation layer disposed therebetween. Thus, when the TFTs as switching elements are turned on by the gate lines, the date lines begin to perform charge on the respective pixel electrodes through the TFTs. All of the pixel electrodes connected with each data line are influenced by the charging voltage on the data line with the parasitic capacitance, so the display voltages of these pixel electrodes may vary slightly and correspondingly, and image sticking may be generated along the direction of the data line on the display screen. Furthermore, in such a pixel structure, a black matrix is formed around and above the pixel electrodes in order to protect the devices provided in the liquid crystal panel from being influenced by exterior light. Light leakage phenomenon may not occur around the pixel electrodes due to the light blocking bars when the liquid crystal display panel is viewed from the front direction. But, when the liquid crystal display panel is viewed from an oblique direction, the light leakage phenomenon may be serious compared with the front direction.